Photographic gauss type objective

ABSTRACT

A photographic Gauss type objective is disclosed which comprises five meniscus lens members. In front of the objective diaphragm in the direction of light travel are aligned one single converging meniscus and one cemented negative meniscus. Behind the diaphragm are arranged three single meniscus lens members whereof the first one is negative while the remaining two are positive. The objective has a relative aperture of at least f:2.8, a field angle of + or - 18*, and it can be used in an image scale field ranging from oo:1 to 1:1.

SR TLWWA/ Jan. 5,1971

H.MAR' 5UA RDT PHOTOGRAPHIC GAUSS TYPE OBJECTIVE Filed Dec. 2, 1968 "WENT/1H Heinz Marquardf Y v ww ATTORNEYS United States Patent'() 3,552,833 PHOTOGRAPHIC GAUSS TYPE OBJECTIVE Heinz Marquardt, Wetzlar, Germany, assignor to Firma Ernst Leitz, G.m.b.H., Wetzlar, Germany Filed Dec. 2, 1968, Ser. No. 780,428 Claims priority, application Germany, Dec. 30, 1967, 1,269,385 Int. Cl. G02b 9/60 US. Cl. 350217 1 Claim ABSTRACT OF THE DISCLOSURE A photographic Gauss type objective is disclosed which comprises five meniscus lens members. In front of the objective diaphragm in the direction of light travel are aligned one singlet converging meniscus and one cemented negative meniscus. Behind the diaphragm are arranged three singlet meniscus lens members whereof the first one is negative while the remaining two are positive. The

objective has a relative aperture of at least f:2.8, a field angle of :18, and it can be used in an image scale field ranging from :1 to 1:1.

BACKGROUND OF THE INVENTION It is an object of the present invention to provide a photographic objective which can be used in an image scale field ranging from 06:1 to 1:1 and which represents an acceptable and even favorable compromise of image errors at all required image scales.

SUMMARY OF THE INVENTION.

The above stated object is attained by constructing an objective, comprising one singlet positive meniscus and one cemented negative meniscus in front of the diaphragm and one singlet negative and two singlet positive meniscus lens members behind the diaphragm, according to the specifications set forth in the following table for which the focal length equals 1 and wherein:

r to r represents the radii of successive lens surfaces,

d to d represents the axial thickness of the respective lenses,

a to 0 represents the axial spacings between the respective lenses,

n and v represent respectively the refractive indices and Abbe numbers of the lens materials,

An/r represents the refractive power of the respective lens surface, which data could also be written as wherein n is the refractive index of the material behind the surface, n is the refractive index of the material in front of the surface, and r is the radius of the surface, and

s represents the back focal distance.

The table is to be read in connection with the drawing which represents a view of an objective incorporating the invention and cut along the optical axis.

" Ce 3,552,833 Patented Jan. 5, 1971 Thicknesses Radil and spacings 71,, v An/r lll=0.0600 1. 74795 14. n= +1.2005 -0. 575567 d2=0.1029 1. 69282 40. 5 T4=+Ll521 -0. 013175 a =0.2234 rs=0.20 3. 666831 dl=0.0a59 1. 74070 26. 2 7 0.2853 +2. 596214 fl3=0.0028 r =1.l428 0. 545038 d =0.O-l32 1.62287 60.1

(la=0.0440 1. 61521 58. 4 n1= -0.3237 +1. 900556 s'=0.6838 2.0 :(d+a1=0.5s71

Variations from the above thicknesses and spacings data can be tolerated if they do not exceed :10%. From the surface refractive powers (An/r) variations can be per- 20 mitted in a range of 120%. The latter variations may be attained by a change of the radii and/ or by variations in the refractive index of the used glass types.

What is claimedis: 1. A photographic Gauss type objective having a relative aperture of at least :2.8 and a field angle of 218, said objective comprising in the direction of light travel one singlet positive meniscus and one cemented negative meniscus in front of the diaphragm and one singlet negative and two singlet positive meniscus lens 00 members behind said diaphragm, said lens members having sub tantially the following approximate specifications:

Thicknesses Radii and spacings 72., v8 An/r dl=0.0600 1. 74795 44. 5 r2=+1.2995 -0. 575567 dz! =0.1029 1. 69282 49. 5 r4=+1.1521 -0. 013175 4'.) d =0.0331 1. 67764 32. 0

a =O.0028 T3=-1.1428 -0.545038 wherein the data given for the thicknesses, spacings and radii are expressed in multiples of the focal length of the objective.

References Cited UNITED STATES PATENTS 2,831,397 4/1958 Berger et a1. 350216X JOHN K. CORBIN, Primary Examiner 

